Synthesis, Crystal Structure And Properties Research Of Polyoxometalate Containing Tungsten

Nine new polyoxometalate compounds, which are decorated or bridged by various transition complexes, are synthesized by aqueous solution method on the basis of W12O42, W18O56 polyoxoanion clusters. The chemical formulas of nine compounds can be made by elemental analyses and TG analysis:[Na2M(OH)6W6O18] (imi)2·2H3O (M=Fe(1), Cu(2),Ni(3))[{Cu(bim)(H2O)2｝4(H4W12O42)]·14H2O(4)(Himi)6[{Mn(imi)(H2O)}(H4W12O42)]·2H2O(5)[{Cu0.5(H2O)}2{Cu0.5(H2O)2}2{Cu(bim)(H2O)2}2(H4W12O42)]·10H2O(6)[{Na(H20)4}2{Cu0.5(H2O)}4{Cu0.5 (H2O)1.5}2(H4W12O42)]·3H2O (7)[｛Na(H2O)4.5｝2(H5W12O42)][｛Na5(H2O)16｝｛Cu(H2O)2｝4(H4W12042)]·13H2O(8)(Himi)6[H3W18O56Na(OH)6]·4H2O(9)The structure of compounds are characterized by IR, TG and single crystal X-ray diffractions. The result shows that compounds 1-3 are isostructural. Furthermore, each [MW6(OH)6O18]4-(M=Fe2+, Cu2+, Ni2+) anion links six Na+ cations via terminal atoms of the polyoxoanion and each Na+ cation also links three polyoxoanions to form 3D structure. The imidazoles dissociate in the cavity between the polyoxoanions and Na+ cations. Compounds 4 is formed into isolated structure,{Cu(bim)(H2O)2}2+ fragments modifying [H4W12042]8- polyoxoanion. The compound 5 is an infinite 1D "wave-like" chain linked by [H4W12O42]8- polyanion and [Mn(imi)(H2O)]2+. Compound 6 is 2D layer structure formed by the interaction of 1D [{Cu0.5(H2O)}2(H4W12042)]6- and [{Cu0.5(H2O)2}2(H4W12O42)]6- chains. While compound 7 is 3D network, abbreviated to (6,2)-connected. Compound 8 is a 3D framework which is formed by 2D layer formed by two 1D chains of [{Cu(H2O)}2(H4W12O42)]n6- and [Na5(H2O)]6]n5+ chains. Compound 9 is isolated structure of Dawson-like.In addition, the electrochemical properties of these compounds are researched.